1 /*
2  * drivers/pci/pcie/aer/aerdrv_core.c
3  *
4  * This file is subject to the terms and conditions of the GNU General Public
5  * License.  See the file "COPYING" in the main directory of this archive
6  * for more details.
7  *
8  * This file implements the core part of PCI-Express AER. When an pci-express
9  * error is delivered, an error message will be collected and printed to
10  * console, then, an error recovery procedure will be executed by following
11  * the pci error recovery rules.
12  *
13  * Copyright (C) 2006 Intel Corp.
14  *	Tom Long Nguyen (tom.l.nguyen@intel.com)
15  *	Zhang Yanmin (yanmin.zhang@intel.com)
16  *
17  */
18 
19 #include <linux/module.h>
20 #include <linux/pci.h>
21 #include <linux/kernel.h>
22 #include <linux/errno.h>
23 #include <linux/pm.h>
24 #include <linux/suspend.h>
25 #include <linux/delay.h>
26 #include <linux/slab.h>
27 #include <linux/kfifo.h>
28 #include "aerdrv.h"
29 
30 static bool forceload;
31 static bool nosourceid;
32 module_param(forceload, bool, 0);
33 module_param(nosourceid, bool, 0);
34 
35 #define	PCI_EXP_AER_FLAGS	(PCI_EXP_DEVCTL_CERE | PCI_EXP_DEVCTL_NFERE | \
36 				 PCI_EXP_DEVCTL_FERE | PCI_EXP_DEVCTL_URRE)
37 
pci_enable_pcie_error_reporting(struct pci_dev * dev)38 int pci_enable_pcie_error_reporting(struct pci_dev *dev)
39 {
40 	if (pcie_aer_get_firmware_first(dev))
41 		return -EIO;
42 
43 	if (!pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR))
44 		return -EIO;
45 
46 	return pcie_capability_set_word(dev, PCI_EXP_DEVCTL, PCI_EXP_AER_FLAGS);
47 }
48 EXPORT_SYMBOL_GPL(pci_enable_pcie_error_reporting);
49 
pci_disable_pcie_error_reporting(struct pci_dev * dev)50 int pci_disable_pcie_error_reporting(struct pci_dev *dev)
51 {
52 	if (pcie_aer_get_firmware_first(dev))
53 		return -EIO;
54 
55 	return pcie_capability_clear_word(dev, PCI_EXP_DEVCTL,
56 					  PCI_EXP_AER_FLAGS);
57 }
58 EXPORT_SYMBOL_GPL(pci_disable_pcie_error_reporting);
59 
pci_cleanup_aer_uncorrect_error_status(struct pci_dev * dev)60 int pci_cleanup_aer_uncorrect_error_status(struct pci_dev *dev)
61 {
62 	int pos;
63 	u32 status;
64 
65 	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
66 	if (!pos)
67 		return -EIO;
68 
69 	pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status);
70 	if (status)
71 		pci_write_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, status);
72 
73 	return 0;
74 }
75 EXPORT_SYMBOL_GPL(pci_cleanup_aer_uncorrect_error_status);
76 
77 /**
78  * add_error_device - list device to be handled
79  * @e_info: pointer to error info
80  * @dev: pointer to pci_dev to be added
81  */
add_error_device(struct aer_err_info * e_info,struct pci_dev * dev)82 static int add_error_device(struct aer_err_info *e_info, struct pci_dev *dev)
83 {
84 	if (e_info->error_dev_num < AER_MAX_MULTI_ERR_DEVICES) {
85 		e_info->dev[e_info->error_dev_num] = dev;
86 		e_info->error_dev_num++;
87 		return 0;
88 	}
89 	return -ENOSPC;
90 }
91 
92 /**
93  * is_error_source - check whether the device is source of reported error
94  * @dev: pointer to pci_dev to be checked
95  * @e_info: pointer to reported error info
96  */
is_error_source(struct pci_dev * dev,struct aer_err_info * e_info)97 static bool is_error_source(struct pci_dev *dev, struct aer_err_info *e_info)
98 {
99 	int pos;
100 	u32 status, mask;
101 	u16 reg16;
102 
103 	/*
104 	 * When bus id is equal to 0, it might be a bad id
105 	 * reported by root port.
106 	 */
107 	if (!nosourceid && (PCI_BUS_NUM(e_info->id) != 0)) {
108 		/* Device ID match? */
109 		if (e_info->id == ((dev->bus->number << 8) | dev->devfn))
110 			return true;
111 
112 		/* Continue id comparing if there is no multiple error */
113 		if (!e_info->multi_error_valid)
114 			return false;
115 	}
116 
117 	/*
118 	 * When either
119 	 *      1) nosourceid==y;
120 	 *      2) bus id is equal to 0. Some ports might lose the bus
121 	 *              id of error source id;
122 	 *      3) There are multiple errors and prior id comparing fails;
123 	 * We check AER status registers to find possible reporter.
124 	 */
125 	if (atomic_read(&dev->enable_cnt) == 0)
126 		return false;
127 
128 	/* Check if AER is enabled */
129 	pcie_capability_read_word(dev, PCI_EXP_DEVCTL, &reg16);
130 	if (!(reg16 & PCI_EXP_AER_FLAGS))
131 		return false;
132 
133 	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
134 	if (!pos)
135 		return false;
136 
137 	/* Check if error is recorded */
138 	if (e_info->severity == AER_CORRECTABLE) {
139 		pci_read_config_dword(dev, pos + PCI_ERR_COR_STATUS, &status);
140 		pci_read_config_dword(dev, pos + PCI_ERR_COR_MASK, &mask);
141 	} else {
142 		pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS, &status);
143 		pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_MASK, &mask);
144 	}
145 	if (status & ~mask)
146 		return true;
147 
148 	return false;
149 }
150 
find_device_iter(struct pci_dev * dev,void * data)151 static int find_device_iter(struct pci_dev *dev, void *data)
152 {
153 	struct aer_err_info *e_info = (struct aer_err_info *)data;
154 
155 	if (is_error_source(dev, e_info)) {
156 		/* List this device */
157 		if (add_error_device(e_info, dev)) {
158 			/* We cannot handle more... Stop iteration */
159 			/* TODO: Should print error message here? */
160 			return 1;
161 		}
162 
163 		/* If there is only a single error, stop iteration */
164 		if (!e_info->multi_error_valid)
165 			return 1;
166 	}
167 	return 0;
168 }
169 
170 /**
171  * find_source_device - search through device hierarchy for source device
172  * @parent: pointer to Root Port pci_dev data structure
173  * @e_info: including detailed error information such like id
174  *
175  * Return true if found.
176  *
177  * Invoked by DPC when error is detected at the Root Port.
178  * Caller of this function must set id, severity, and multi_error_valid of
179  * struct aer_err_info pointed by @e_info properly.  This function must fill
180  * e_info->error_dev_num and e_info->dev[], based on the given information.
181  */
find_source_device(struct pci_dev * parent,struct aer_err_info * e_info)182 static bool find_source_device(struct pci_dev *parent,
183 		struct aer_err_info *e_info)
184 {
185 	struct pci_dev *dev = parent;
186 	int result;
187 
188 	/* Must reset in this function */
189 	e_info->error_dev_num = 0;
190 
191 	/* Is Root Port an agent that sends error message? */
192 	result = find_device_iter(dev, e_info);
193 	if (result)
194 		return true;
195 
196 	pci_walk_bus(parent->subordinate, find_device_iter, e_info);
197 
198 	if (!e_info->error_dev_num) {
199 		dev_printk(KERN_DEBUG, &parent->dev,
200 				"can't find device of ID%04x\n",
201 				e_info->id);
202 		return false;
203 	}
204 	return true;
205 }
206 
report_error_detected(struct pci_dev * dev,void * data)207 static int report_error_detected(struct pci_dev *dev, void *data)
208 {
209 	pci_ers_result_t vote;
210 	const struct pci_error_handlers *err_handler;
211 	struct aer_broadcast_data *result_data;
212 	result_data = (struct aer_broadcast_data *) data;
213 
214 	device_lock(&dev->dev);
215 	dev->error_state = result_data->state;
216 
217 	if (!dev->driver ||
218 		!dev->driver->err_handler ||
219 		!dev->driver->err_handler->error_detected) {
220 		if (result_data->state == pci_channel_io_frozen &&
221 			!(dev->hdr_type & PCI_HEADER_TYPE_BRIDGE)) {
222 			/*
223 			 * In case of fatal recovery, if one of down-
224 			 * stream device has no driver. We might be
225 			 * unable to recover because a later insmod
226 			 * of a driver for this device is unaware of
227 			 * its hw state.
228 			 */
229 			dev_printk(KERN_DEBUG, &dev->dev, "device has %s\n",
230 				   dev->driver ?
231 				   "no AER-aware driver" : "no driver");
232 		}
233 
234 		/*
235 		 * If there's any device in the subtree that does not
236 		 * have an error_detected callback, returning
237 		 * PCI_ERS_RESULT_NO_AER_DRIVER prevents calling of
238 		 * the subsequent mmio_enabled/slot_reset/resume
239 		 * callbacks of "any" device in the subtree. All the
240 		 * devices in the subtree are left in the error state
241 		 * without recovery.
242 		 */
243 
244 		if (!(dev->hdr_type & PCI_HEADER_TYPE_BRIDGE))
245 			vote = PCI_ERS_RESULT_NO_AER_DRIVER;
246 		else
247 			vote = PCI_ERS_RESULT_NONE;
248 	} else {
249 		err_handler = dev->driver->err_handler;
250 		vote = err_handler->error_detected(dev, result_data->state);
251 	}
252 
253 	result_data->result = merge_result(result_data->result, vote);
254 	device_unlock(&dev->dev);
255 	return 0;
256 }
257 
report_mmio_enabled(struct pci_dev * dev,void * data)258 static int report_mmio_enabled(struct pci_dev *dev, void *data)
259 {
260 	pci_ers_result_t vote;
261 	const struct pci_error_handlers *err_handler;
262 	struct aer_broadcast_data *result_data;
263 	result_data = (struct aer_broadcast_data *) data;
264 
265 	device_lock(&dev->dev);
266 	if (!dev->driver ||
267 		!dev->driver->err_handler ||
268 		!dev->driver->err_handler->mmio_enabled)
269 		goto out;
270 
271 	err_handler = dev->driver->err_handler;
272 	vote = err_handler->mmio_enabled(dev);
273 	result_data->result = merge_result(result_data->result, vote);
274 out:
275 	device_unlock(&dev->dev);
276 	return 0;
277 }
278 
report_slot_reset(struct pci_dev * dev,void * data)279 static int report_slot_reset(struct pci_dev *dev, void *data)
280 {
281 	pci_ers_result_t vote;
282 	const struct pci_error_handlers *err_handler;
283 	struct aer_broadcast_data *result_data;
284 	result_data = (struct aer_broadcast_data *) data;
285 
286 	device_lock(&dev->dev);
287 	if (!dev->driver ||
288 		!dev->driver->err_handler ||
289 		!dev->driver->err_handler->slot_reset)
290 		goto out;
291 
292 	err_handler = dev->driver->err_handler;
293 	vote = err_handler->slot_reset(dev);
294 	result_data->result = merge_result(result_data->result, vote);
295 out:
296 	device_unlock(&dev->dev);
297 	return 0;
298 }
299 
report_resume(struct pci_dev * dev,void * data)300 static int report_resume(struct pci_dev *dev, void *data)
301 {
302 	const struct pci_error_handlers *err_handler;
303 
304 	device_lock(&dev->dev);
305 	dev->error_state = pci_channel_io_normal;
306 
307 	if (!dev->driver ||
308 		!dev->driver->err_handler ||
309 		!dev->driver->err_handler->resume)
310 		goto out;
311 
312 	err_handler = dev->driver->err_handler;
313 	err_handler->resume(dev);
314 out:
315 	device_unlock(&dev->dev);
316 	return 0;
317 }
318 
319 /**
320  * broadcast_error_message - handle message broadcast to downstream drivers
321  * @dev: pointer to from where in a hierarchy message is broadcasted down
322  * @state: error state
323  * @error_mesg: message to print
324  * @cb: callback to be broadcasted
325  *
326  * Invoked during error recovery process. Once being invoked, the content
327  * of error severity will be broadcasted to all downstream drivers in a
328  * hierarchy in question.
329  */
broadcast_error_message(struct pci_dev * dev,enum pci_channel_state state,char * error_mesg,int (* cb)(struct pci_dev *,void *))330 static pci_ers_result_t broadcast_error_message(struct pci_dev *dev,
331 	enum pci_channel_state state,
332 	char *error_mesg,
333 	int (*cb)(struct pci_dev *, void *))
334 {
335 	struct aer_broadcast_data result_data;
336 
337 	dev_printk(KERN_DEBUG, &dev->dev, "broadcast %s message\n", error_mesg);
338 	result_data.state = state;
339 	if (cb == report_error_detected)
340 		result_data.result = PCI_ERS_RESULT_CAN_RECOVER;
341 	else
342 		result_data.result = PCI_ERS_RESULT_RECOVERED;
343 
344 	if (dev->hdr_type & PCI_HEADER_TYPE_BRIDGE) {
345 		/*
346 		 * If the error is reported by a bridge, we think this error
347 		 * is related to the downstream link of the bridge, so we
348 		 * do error recovery on all subordinates of the bridge instead
349 		 * of the bridge and clear the error status of the bridge.
350 		 */
351 		if (cb == report_error_detected)
352 			dev->error_state = state;
353 		pci_walk_bus(dev->subordinate, cb, &result_data);
354 		if (cb == report_resume) {
355 			pci_cleanup_aer_uncorrect_error_status(dev);
356 			dev->error_state = pci_channel_io_normal;
357 		}
358 	} else {
359 		/*
360 		 * If the error is reported by an end point, we think this
361 		 * error is related to the upstream link of the end point.
362 		 */
363 		pci_walk_bus(dev->bus, cb, &result_data);
364 	}
365 
366 	return result_data.result;
367 }
368 
369 /**
370  * default_reset_link - default reset function
371  * @dev: pointer to pci_dev data structure
372  *
373  * Invoked when performing link reset on a Downstream Port or a
374  * Root Port with no aer driver.
375  */
default_reset_link(struct pci_dev * dev)376 static pci_ers_result_t default_reset_link(struct pci_dev *dev)
377 {
378 	pci_reset_bridge_secondary_bus(dev);
379 	dev_printk(KERN_DEBUG, &dev->dev, "downstream link has been reset\n");
380 	return PCI_ERS_RESULT_RECOVERED;
381 }
382 
find_aer_service_iter(struct device * device,void * data)383 static int find_aer_service_iter(struct device *device, void *data)
384 {
385 	struct pcie_port_service_driver *service_driver, **drv;
386 
387 	drv = (struct pcie_port_service_driver **) data;
388 
389 	if (device->bus == &pcie_port_bus_type && device->driver) {
390 		service_driver = to_service_driver(device->driver);
391 		if (service_driver->service == PCIE_PORT_SERVICE_AER) {
392 			*drv = service_driver;
393 			return 1;
394 		}
395 	}
396 
397 	return 0;
398 }
399 
find_aer_service(struct pci_dev * dev)400 static struct pcie_port_service_driver *find_aer_service(struct pci_dev *dev)
401 {
402 	struct pcie_port_service_driver *drv = NULL;
403 
404 	device_for_each_child(&dev->dev, &drv, find_aer_service_iter);
405 
406 	return drv;
407 }
408 
reset_link(struct pci_dev * dev)409 static pci_ers_result_t reset_link(struct pci_dev *dev)
410 {
411 	struct pci_dev *udev;
412 	pci_ers_result_t status;
413 	struct pcie_port_service_driver *driver;
414 
415 	if (dev->hdr_type & PCI_HEADER_TYPE_BRIDGE) {
416 		/* Reset this port for all subordinates */
417 		udev = dev;
418 	} else {
419 		/* Reset the upstream component (likely downstream port) */
420 		udev = dev->bus->self;
421 	}
422 
423 	/* Use the aer driver of the component firstly */
424 	driver = find_aer_service(udev);
425 
426 	if (driver && driver->reset_link) {
427 		status = driver->reset_link(udev);
428 	} else if (pci_pcie_type(udev) == PCI_EXP_TYPE_DOWNSTREAM ||
429 		pci_pcie_type(udev) == PCI_EXP_TYPE_ROOT_PORT) {
430 		status = default_reset_link(udev);
431 	} else {
432 		dev_printk(KERN_DEBUG, &dev->dev,
433 			"no link-reset support at upstream device %s\n",
434 			pci_name(udev));
435 		return PCI_ERS_RESULT_DISCONNECT;
436 	}
437 
438 	if (status != PCI_ERS_RESULT_RECOVERED) {
439 		dev_printk(KERN_DEBUG, &dev->dev,
440 			"link reset at upstream device %s failed\n",
441 			pci_name(udev));
442 		return PCI_ERS_RESULT_DISCONNECT;
443 	}
444 
445 	return status;
446 }
447 
448 /**
449  * do_recovery - handle nonfatal/fatal error recovery process
450  * @dev: pointer to a pci_dev data structure of agent detecting an error
451  * @severity: error severity type
452  *
453  * Invoked when an error is nonfatal/fatal. Once being invoked, broadcast
454  * error detected message to all downstream drivers within a hierarchy in
455  * question and return the returned code.
456  */
do_recovery(struct pci_dev * dev,int severity)457 static void do_recovery(struct pci_dev *dev, int severity)
458 {
459 	pci_ers_result_t status, result = PCI_ERS_RESULT_RECOVERED;
460 	enum pci_channel_state state;
461 
462 	if (severity == AER_FATAL)
463 		state = pci_channel_io_frozen;
464 	else
465 		state = pci_channel_io_normal;
466 
467 	status = broadcast_error_message(dev,
468 			state,
469 			"error_detected",
470 			report_error_detected);
471 
472 	if (severity == AER_FATAL) {
473 		result = reset_link(dev);
474 		if (result != PCI_ERS_RESULT_RECOVERED)
475 			goto failed;
476 	}
477 
478 	if (status == PCI_ERS_RESULT_CAN_RECOVER)
479 		status = broadcast_error_message(dev,
480 				state,
481 				"mmio_enabled",
482 				report_mmio_enabled);
483 
484 	if (status == PCI_ERS_RESULT_NEED_RESET) {
485 		/*
486 		 * TODO: Should call platform-specific
487 		 * functions to reset slot before calling
488 		 * drivers' slot_reset callbacks?
489 		 */
490 		status = broadcast_error_message(dev,
491 				state,
492 				"slot_reset",
493 				report_slot_reset);
494 	}
495 
496 	if (status != PCI_ERS_RESULT_RECOVERED)
497 		goto failed;
498 
499 	broadcast_error_message(dev,
500 				state,
501 				"resume",
502 				report_resume);
503 
504 	dev_info(&dev->dev, "AER: Device recovery successful\n");
505 	return;
506 
507 failed:
508 	/* TODO: Should kernel panic here? */
509 	dev_info(&dev->dev, "AER: Device recovery failed\n");
510 }
511 
512 /**
513  * handle_error_source - handle logging error into an event log
514  * @aerdev: pointer to pcie_device data structure of the root port
515  * @dev: pointer to pci_dev data structure of error source device
516  * @info: comprehensive error information
517  *
518  * Invoked when an error being detected by Root Port.
519  */
handle_error_source(struct pcie_device * aerdev,struct pci_dev * dev,struct aer_err_info * info)520 static void handle_error_source(struct pcie_device *aerdev,
521 	struct pci_dev *dev,
522 	struct aer_err_info *info)
523 {
524 	int pos;
525 
526 	if (info->severity == AER_CORRECTABLE) {
527 		/*
528 		 * Correctable error does not need software intervention.
529 		 * No need to go through error recovery process.
530 		 */
531 		pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
532 		if (pos)
533 			pci_write_config_dword(dev, pos + PCI_ERR_COR_STATUS,
534 					info->status);
535 	} else
536 		do_recovery(dev, info->severity);
537 }
538 
539 #ifdef CONFIG_ACPI_APEI_PCIEAER
540 static void aer_recover_work_func(struct work_struct *work);
541 
542 #define AER_RECOVER_RING_ORDER		4
543 #define AER_RECOVER_RING_SIZE		(1 << AER_RECOVER_RING_ORDER)
544 
545 struct aer_recover_entry {
546 	u8	bus;
547 	u8	devfn;
548 	u16	domain;
549 	int	severity;
550 	struct aer_capability_regs *regs;
551 };
552 
553 static DEFINE_KFIFO(aer_recover_ring, struct aer_recover_entry,
554 		    AER_RECOVER_RING_SIZE);
555 /*
556  * Mutual exclusion for writers of aer_recover_ring, reader side don't
557  * need lock, because there is only one reader and lock is not needed
558  * between reader and writer.
559  */
560 static DEFINE_SPINLOCK(aer_recover_ring_lock);
561 static DECLARE_WORK(aer_recover_work, aer_recover_work_func);
562 
aer_recover_queue(int domain,unsigned int bus,unsigned int devfn,int severity,struct aer_capability_regs * aer_regs)563 void aer_recover_queue(int domain, unsigned int bus, unsigned int devfn,
564 		       int severity, struct aer_capability_regs *aer_regs)
565 {
566 	unsigned long flags;
567 	struct aer_recover_entry entry = {
568 		.bus		= bus,
569 		.devfn		= devfn,
570 		.domain		= domain,
571 		.severity	= severity,
572 		.regs		= aer_regs,
573 	};
574 
575 	spin_lock_irqsave(&aer_recover_ring_lock, flags);
576 	if (kfifo_put(&aer_recover_ring, entry))
577 		schedule_work(&aer_recover_work);
578 	else
579 		pr_err("AER recover: Buffer overflow when recovering AER for %04x:%02x:%02x:%x\n",
580 		       domain, bus, PCI_SLOT(devfn), PCI_FUNC(devfn));
581 	spin_unlock_irqrestore(&aer_recover_ring_lock, flags);
582 }
583 EXPORT_SYMBOL_GPL(aer_recover_queue);
584 
aer_recover_work_func(struct work_struct * work)585 static void aer_recover_work_func(struct work_struct *work)
586 {
587 	struct aer_recover_entry entry;
588 	struct pci_dev *pdev;
589 
590 	while (kfifo_get(&aer_recover_ring, &entry)) {
591 		pdev = pci_get_domain_bus_and_slot(entry.domain, entry.bus,
592 						   entry.devfn);
593 		if (!pdev) {
594 			pr_err("AER recover: Can not find pci_dev for %04x:%02x:%02x:%x\n",
595 			       entry.domain, entry.bus,
596 			       PCI_SLOT(entry.devfn), PCI_FUNC(entry.devfn));
597 			continue;
598 		}
599 		cper_print_aer(pdev, entry.severity, entry.regs);
600 		do_recovery(pdev, entry.severity);
601 		pci_dev_put(pdev);
602 	}
603 }
604 #endif
605 
606 /**
607  * get_device_error_info - read error status from dev and store it to info
608  * @dev: pointer to the device expected to have a error record
609  * @info: pointer to structure to store the error record
610  *
611  * Return 1 on success, 0 on error.
612  *
613  * Note that @info is reused among all error devices. Clear fields properly.
614  */
get_device_error_info(struct pci_dev * dev,struct aer_err_info * info)615 static int get_device_error_info(struct pci_dev *dev, struct aer_err_info *info)
616 {
617 	int pos, temp;
618 
619 	/* Must reset in this function */
620 	info->status = 0;
621 	info->tlp_header_valid = 0;
622 
623 	pos = pci_find_ext_capability(dev, PCI_EXT_CAP_ID_ERR);
624 
625 	/* The device might not support AER */
626 	if (!pos)
627 		return 1;
628 
629 	if (info->severity == AER_CORRECTABLE) {
630 		pci_read_config_dword(dev, pos + PCI_ERR_COR_STATUS,
631 			&info->status);
632 		pci_read_config_dword(dev, pos + PCI_ERR_COR_MASK,
633 			&info->mask);
634 		if (!(info->status & ~info->mask))
635 			return 0;
636 	} else if (dev->hdr_type & PCI_HEADER_TYPE_BRIDGE ||
637 		info->severity == AER_NONFATAL) {
638 
639 		/* Link is still healthy for IO reads */
640 		pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_STATUS,
641 			&info->status);
642 		pci_read_config_dword(dev, pos + PCI_ERR_UNCOR_MASK,
643 			&info->mask);
644 		if (!(info->status & ~info->mask))
645 			return 0;
646 
647 		/* Get First Error Pointer */
648 		pci_read_config_dword(dev, pos + PCI_ERR_CAP, &temp);
649 		info->first_error = PCI_ERR_CAP_FEP(temp);
650 
651 		if (info->status & AER_LOG_TLP_MASKS) {
652 			info->tlp_header_valid = 1;
653 			pci_read_config_dword(dev,
654 				pos + PCI_ERR_HEADER_LOG, &info->tlp.dw0);
655 			pci_read_config_dword(dev,
656 				pos + PCI_ERR_HEADER_LOG + 4, &info->tlp.dw1);
657 			pci_read_config_dword(dev,
658 				pos + PCI_ERR_HEADER_LOG + 8, &info->tlp.dw2);
659 			pci_read_config_dword(dev,
660 				pos + PCI_ERR_HEADER_LOG + 12, &info->tlp.dw3);
661 		}
662 	}
663 
664 	return 1;
665 }
666 
aer_process_err_devices(struct pcie_device * p_device,struct aer_err_info * e_info)667 static inline void aer_process_err_devices(struct pcie_device *p_device,
668 			struct aer_err_info *e_info)
669 {
670 	int i;
671 
672 	/* Report all before handle them, not to lost records by reset etc. */
673 	for (i = 0; i < e_info->error_dev_num && e_info->dev[i]; i++) {
674 		if (get_device_error_info(e_info->dev[i], e_info))
675 			aer_print_error(e_info->dev[i], e_info);
676 	}
677 	for (i = 0; i < e_info->error_dev_num && e_info->dev[i]; i++) {
678 		if (get_device_error_info(e_info->dev[i], e_info))
679 			handle_error_source(p_device, e_info->dev[i], e_info);
680 	}
681 }
682 
683 /**
684  * aer_isr_one_error - consume an error detected by root port
685  * @p_device: pointer to error root port service device
686  * @e_src: pointer to an error source
687  */
aer_isr_one_error(struct pcie_device * p_device,struct aer_err_source * e_src)688 static void aer_isr_one_error(struct pcie_device *p_device,
689 		struct aer_err_source *e_src)
690 {
691 	struct aer_err_info *e_info;
692 
693 	/* struct aer_err_info might be big, so we allocate it with slab */
694 	e_info = kmalloc(sizeof(struct aer_err_info), GFP_KERNEL);
695 	if (!e_info) {
696 		dev_printk(KERN_DEBUG, &p_device->port->dev,
697 			"Can't allocate mem when processing AER errors\n");
698 		return;
699 	}
700 
701 	/*
702 	 * There is a possibility that both correctable error and
703 	 * uncorrectable error being logged. Report correctable error first.
704 	 */
705 	if (e_src->status & PCI_ERR_ROOT_COR_RCV) {
706 		e_info->id = ERR_COR_ID(e_src->id);
707 		e_info->severity = AER_CORRECTABLE;
708 
709 		if (e_src->status & PCI_ERR_ROOT_MULTI_COR_RCV)
710 			e_info->multi_error_valid = 1;
711 		else
712 			e_info->multi_error_valid = 0;
713 
714 		aer_print_port_info(p_device->port, e_info);
715 
716 		if (find_source_device(p_device->port, e_info))
717 			aer_process_err_devices(p_device, e_info);
718 	}
719 
720 	if (e_src->status & PCI_ERR_ROOT_UNCOR_RCV) {
721 		e_info->id = ERR_UNCOR_ID(e_src->id);
722 
723 		if (e_src->status & PCI_ERR_ROOT_FATAL_RCV)
724 			e_info->severity = AER_FATAL;
725 		else
726 			e_info->severity = AER_NONFATAL;
727 
728 		if (e_src->status & PCI_ERR_ROOT_MULTI_UNCOR_RCV)
729 			e_info->multi_error_valid = 1;
730 		else
731 			e_info->multi_error_valid = 0;
732 
733 		aer_print_port_info(p_device->port, e_info);
734 
735 		if (find_source_device(p_device->port, e_info))
736 			aer_process_err_devices(p_device, e_info);
737 	}
738 
739 	kfree(e_info);
740 }
741 
742 /**
743  * get_e_source - retrieve an error source
744  * @rpc: pointer to the root port which holds an error
745  * @e_src: pointer to store retrieved error source
746  *
747  * Return 1 if an error source is retrieved, otherwise 0.
748  *
749  * Invoked by DPC handler to consume an error.
750  */
get_e_source(struct aer_rpc * rpc,struct aer_err_source * e_src)751 static int get_e_source(struct aer_rpc *rpc, struct aer_err_source *e_src)
752 {
753 	unsigned long flags;
754 
755 	/* Lock access to Root error producer/consumer index */
756 	spin_lock_irqsave(&rpc->e_lock, flags);
757 	if (rpc->prod_idx == rpc->cons_idx) {
758 		spin_unlock_irqrestore(&rpc->e_lock, flags);
759 		return 0;
760 	}
761 
762 	*e_src = rpc->e_sources[rpc->cons_idx];
763 	rpc->cons_idx++;
764 	if (rpc->cons_idx == AER_ERROR_SOURCES_MAX)
765 		rpc->cons_idx = 0;
766 	spin_unlock_irqrestore(&rpc->e_lock, flags);
767 
768 	return 1;
769 }
770 
771 /**
772  * aer_isr - consume errors detected by root port
773  * @work: definition of this work item
774  *
775  * Invoked, as DPC, when root port records new detected error
776  */
aer_isr(struct work_struct * work)777 void aer_isr(struct work_struct *work)
778 {
779 	struct aer_rpc *rpc = container_of(work, struct aer_rpc, dpc_handler);
780 	struct pcie_device *p_device = rpc->rpd;
781 	struct aer_err_source uninitialized_var(e_src);
782 
783 	mutex_lock(&rpc->rpc_mutex);
784 	while (get_e_source(rpc, &e_src))
785 		aer_isr_one_error(p_device, &e_src);
786 	mutex_unlock(&rpc->rpc_mutex);
787 }
788 
789 /**
790  * aer_init - provide AER initialization
791  * @dev: pointer to AER pcie device
792  *
793  * Invoked when AER service driver is loaded.
794  */
aer_init(struct pcie_device * dev)795 int aer_init(struct pcie_device *dev)
796 {
797 	if (forceload) {
798 		dev_printk(KERN_DEBUG, &dev->device,
799 			   "aerdrv forceload requested.\n");
800 		pcie_aer_force_firmware_first(dev->port, 0);
801 	}
802 	return 0;
803 }
804